1. Field of the Invention
The present invention relates to an insulating window covering formed of transparent flexible material and, more particularly, to such an insulating window covering which utilizes air as the insulating medium.
2. Related Art
In temperate or cold climates, it is desirable to minimize heat losses through windows, especially during the coldest months of the year. It is, of course, well known that so-called storm windows can be used for this purpose, as well as special multi-pane windows. Storm windows and multi-pane windows are generally designed to provide one or more insulating pockets of air that help reduce heat loss through a window. Both solutions, however, are relatively expensive.
Moreover, storm windows present the additional disadvantage that they are typically heavy and cumbersome to remove and store. Because they are normally installed on the outside of a building, storm windows must use relatively heavy, rigid materials such as glass or plexiglass. Their installation can be somewhat hazardous, generally requiring the use of a ladder, and presenting danger of injury to the installer and the possibility of damage to the storm windows. Additionally, the storm windows must be stored with great care to prevent damage.
To address some of the shortcomings of storm windows, multi-pane windows, and the like, a variety of temporary, interior-use insulating covers for windows have been devised. Some interior-use insulating window covers still employ heavy glass or plexiglass, and thus do not eliminate most of the problems of conventional storm windows. However, because wind and precipitation are not a concern inside a building, other temporary insulating windows employ more lightweight, flexible transparent materials. Of these, most comprise a continuous frame that fits within or around a window opening, with one or more sheets of transparent or semi-transparent material extending across the frame. In some of these prior devices, the perimeter frame is designed to frictionally fit into the window opening. Other prior designs include an inflatable portion that can be inflated to snugly hold the insulating window cover frame in the window opening, or involve mechanical fasteners.
In some prior designs, two or more transparent sheets are provided, and the space between the sheets is filled with a gas. The space between the sheets may also be subdivided into separate compartments, and these compartments may be sealed from each other or in fluid communication with each other.
As is apparent from the above description, prior temporary insulating window coverings tend to be complex in design, manufacture or usage. Some of them solve some of the problems associated with heavy storm windows, but do so in a manner that raises other problems. For example, some of them have a poor appearance. Where an insulating window cover includes a perimeter frame, in many cases the frame must be custom made to fit an interior window opening that is not of a standard size. This makes such windows very expensive. Even with standard sizes, there are such a wide variety of standard window shapes and sizes that a producer of such devices would need a very large inventory to meet the wide variety of needs.